Following a steady stream of rider complaints, BART said Monday that starting next week it will start temporarily banning anyone caught fighting, acting unruly or treating the train as a toilet.

Two years in the making, the new state law set to take effect May 6 will allow the agency to issue "prohibition orders" banishing rogue riders from entering BART trains, stations or parking lots for 30 days to a year depending on the offense.

The No. 1 priority for BART police officers will be finding aggressive people who pose a danger to passengers and staff of the Bay Area train line. The agency will ban anyone who commits a misdemeanor or felony offense, which includes assaults, prostitution and drug dealing.

Two bicyclists board a BART car near the end of the train with his bicycle during the commute hour at the Fruitvale BART station in Oakland, Calif., on
Two bicyclists board a BART car near the end of the train with his bicycle during the commute hour at the Fruitvale BART station in Oakland, Calif., on Monday, March 18, 2013. BART is conducting a Bike Pilot this week, March 18 -22 where bikes will be allowed on all trains at all time; however, during commute hours (7:00 to 9:00 am and 4:30 to 6:30 pm) bicyclists are asked to not board the first three cars of any trains. (Laura A. Oda/Staff) ( Laura A. Oda )

But three lesser offenses that pile up within 90 days will also lead to a ban. Those include ne'er-do-wells caught going to the bathroom outside of restrooms, tagging BART property with graffiti, blocking passengers from coming or going or carrying hazardous materials on board.

The new law, which applies only to BART but follows similar powers granted to transit agencies in Sacramento and Fresno, was signed by Gov. Jerry Brown in October 2011, but it took until now for the rail line to prepare.

"BART police officers have completed extensive training on applying the law, including ways to work with special needs populations, such as individuals with mental illness or homeless persons," BART police Chief Kenton Rainey said in a statement. "Now it's time to begin using the authority as one of the tools we have to keep our riders and workers safe."

BART employees who work inside the kiosks at stations will have on their computers the names and pictures of any hooligans who are not supposed to be there.

The agency previously had to seek "stay-away" orders with individual county district attorneys to ban unruly passengers, so officials say this latest process will be much easier.

Contact Mike Rosenberg at 408-920-5705. Follow him at twitter.com/RosenbergMerc.