NEW YORK ( CNN ) -- A man accused of entering New York 's LaGuardia Airport with a bag containing wires and batteries , sparking suspicion and leading to a large-scale evacuation , was ordered Saturday to undergo a psychiatric evaluation , a prosecutor said . LaGuardia Airport 's Central Terminal is being treated as a crime scene . Scott McGann , 32 , appeared in court after authorities said he walked into LaGuardia 's Central Terminal Saturday morning with what was determined to be a fake bomb . The terminal was reopened after several hours . Queens District Attorney Richard A . Brown said McGann was charged with placing a false bomb or hazardous substance in the first degree ; placing a false bomb or hazardous substance in a transportation facility ; and making terrorist threats . McGann appeared in court Saturday , but his arraignment was postponed , Brown said . McGann is being held without bail . `` The defendant is clearly a very troubled young man , '' Brown said . `` As a result , the Court has directed that he be examined to determine whether he has the capacity to understand the proceedings against him and assist in his defense . '' Earlier , officials said McGann would n't speak to his lawyer or anyone else . His next court appearance is scheduled for Thursday . McGann allegedly arrived at a checkpoint in the terminal at about 4:50 a.m. , carrying a backpack and refusing to answer security questions . Authorities said the officer at the checkpoint was informed that a suspicious package was attached to the bottom of McGann 's backpack , and that McGann allegedly grabbed what appeared to be a trigger device with a red button connected to the backpack . McGann allegedly pressed the button several times before a Port Authority officer grabbed the trigger and the package away from him . The package turned out to be a device consisting of batteries , cylinders and electronic components that could have been used to make a bomb , Brown said , but the bomb squad found that it did n't not contain any explosives . McGann had a ticket on a United Airlines flight to Chicago and a seat on two other connecting flights with his final destination Oakland , California , according to a law enforcement official close to the investigation . Watch passengers talk about the confusion » . McGann has three prior arrests in the New York area , the source told CNN . The most recent involved June charges of tampering with evidence and resisting arrest . He was also arrested twice in 2008 , the source said . Port Authority spokesman John Kelly said McGann `` was just acting crazy . '' The arresting officers described McGann to Kelly as `` extremely disheveled and dirty , '' in a `` near catatonic state '' and `` staring off into space , '' Kelly said . McGann had been homeless for at least a year . Authorities evacuated the terminal after 5:20 a.m. , and allowed passengers back in to all areas except Concourse C by midmorning , Kelly said . The concourse was reopened shortly before 11 a.m. , according to Federal Aviation Administration spokeswoman Holly Baker . Watch the chaotic evacuation scene » . Authorities had stopped flights from taking off or landing at the airport , but by a little after 9 a.m. , flights resumed , Baker said . Central Terminal is one of four terminals in the airport , which is in the borough of Queens . It is about eight miles from Manhattan . The incident disrupted travel plans for many passengers , and caused American Airlines to cancel 16 flights , said an airline spokesperson . American Eagle , Continental Airlines and Southwest also reported delays . iReport : Watch crowds start moving back into the terminal . CNN i-Reporter Jose Ojeda , 24 , had been sitting on the tarmac on a plane headed to Chicago , Illinois , when the evacuation was ordered . `` We were all ready to go , '' Ojeda , of Bronx , New York , said of his flight , which he said had been scheduled to leave at 6:10 a.m. `` They did n't make any announcement other than , 'You need to evacuate , ' '' he said . `` I thought it was standard procedure , but then once we got out of the plane , they kept pushing us back and back , out of the terminal out of the actual airport . '' CNN 's Chuck Johnston , Aspen Steib , Ross Levitt , Laurie Segall and Susan Candiotti contributed to this report .
Suspect must undergo psychiatric evaluation before court appearance . Scott McGann , 32 , of New York , faces 3 charges , including making terrorist threats . Man had bag stuffed with wires and batteries , appeared intoxicated , official says . Flights resume at busy LaGuardia Airport after evacuation ends .