A Rockville-based thrift store owned by a mental illness nonprofit was burglarized Friday night, dealing a blow to the organization’s ability to operate, directors said.

Business from the thrift store, at 11718 Parklawn Drive, provides roughly 50 percent of the annual funding for the Montgomery County chapter of the National Alliance on Mental Illness, said chapter Executive Director Katherine Slye-Griffin Monday. After damaging the store’s front window and property inside, the crook made off with $274, Slye-Griffin said.

The nonprofit, which provides education and support for people suffering from mental illnesses, including on-the-job training, served more than 2,600 county residents last year, Slye-Griffin said. For fiscal 2011, Slye-Griffin said revenue was $507,324 and expenses will likely be $514,812.

“I’m up to thousands to cover the costs of the damage that was done all because some idiot wanted some change,” she said. “The people who are coming to us really care about our space so to have someone break in was a violation to our staff and our team to have that happen.”

Since the burglar did not take property and the thrift store was not able to provide security camera footage, police are not likely to make an arrest in the case, said Montgomery County police spokeswoman Officer Janelle Smith.

“I don’t want to say it will be impossible, but it’s likely to be very difficult,” Smith said. “When property is taken we’re able to do a bit more in terms of tracking that down, for example we can check pawn records, but when it’s just cash, and it’s not a big enough amount that you would recognize the difference, it’s more difficult.”

Meanwhile, Slye-Griffin is struggling to reclaim the nonprofit’s losses. She sent an email to supporters of the group alerting them of the burglary and is hopeful that the nonprofit’s fundraising event Nov. 17 will enable the group to stay operational.

“We can’t afford security cameras or an alarm; we do a lot with very, very little,” she said of the nonprofit’s plans to add more security measures.

Anyone who witnessed the burglary or has information about the person involved can call Montgomery County police’s non-emergency tip line at 240-773-8477.

Those who wish to learn more about NAMI can visit the nonprofit’s website at www.namimc.org.

jarias@gazette.net